Rotary valve



Aug. 31, 1943. R. WEHR 2,328,115

ROTARY VALVE Filed 061. 12, 1940 55 25 36 22 22 J J 25 Q5 0 Z 20 if? 555 25 4 if ii. 1 .Q.

' F: 7 16 J2 lrfisu'ron ATTORNEY S PatentedA ug. 31, 1943 UNITED STATESPATIENT OFFICE Apphcafizi zc zol 2filz o f e dz loi360,863 8Chims. (c-1Z3-19) The present invention relates to rotary valves,

and more particularly to a type adapted for use 7 in internal combustionengines for controlling the admission and discharge of gases to and fromthe combustion cylinder.

One object of the present invention is to pro- 1 its various operatingparts.

Various other objects of the invention will be apparent from thefollowing particular description, and from an inspection of theaccompanying drawing, in which 7 Fig. 1 is a sectional view of a portionof an'internal combustion engine, provided with a valve mechanismembodying one form of the present invention,

Fig. 2 is a transverse section-oi one of the rotary valves taken on line2-2 of Fig. 1,

Fig 3 is a fragmentary section on an exaggerated scale of a sharpserration, formed on the surface of one of the relatively slidable partsof the valve mechanism, and shown before the sharp edges of its ridgeshave been worn into gas-tight seating contour,

Fig. 4 is a fragmentary section of the serration of Fig. 3 after thesharp edges of the ridges have been worn into gas-tight seating contour,and

Figs. 5 and 6 are transverse sections of differ out forms of valvemechanism respectively, embodying the present invention.

The present application is a continuation in part of my co-pending'application Serial No.

328,503, flledApril 8, 1940.

Referring specifically to Figs. 1 to 4 of the drawing, the invention isshown applied to an engine having a series of combustion cylinders I0,

Iii

closed at one end by a cylinder head I I, provided with a bore I3 forhousing a series of rotary valve members I2 in axial alinement. Thevalve housing II is provided at each section thereof above itscorresponding cylinder III with an intake port ll, an exhaust port I!and a cylinder port [6, disposed between said intake and exhaust ports.Each rotor I2 is provided with two symmetrically arranged recesses orpassageways I1,

adapted to connect the cylinder port It with the intake port I4 andexhaust port IS in proper sequence upon rotation of said rotor.

In the type of rotary valve inwhich the housing serves as a bearing forthe rotor, thepressure exerted by the gases in the cylinder, especiallyduring compression and explosion, tends to lift the rotor away from itsseat at the cylinder port I6 and againstthe section of the housingopposite said seat. This may result in leakage past the valve, and thebinding or seizing of the rotor I against rotation. To avoid this, thevalve secti'ons I2 are supported by intermediate anti-friction bearingsI8, each comprising an outer race I9, affixed at its outer periphery inthe bore' iii of the housing I I, an inner race 20, and a series ofbearing balls 2| between said races. Each valve section I2 is providedat each end with a boss 22 abutting the end of the inner race 20, and ashaft or trunnion 23 of reduced diameter extending axially from saidboss into the bore of said inner race. The opposed shafts 23 ofadjoining rotors l2 are keyed or otherwise afflxed together or to theinner races 20, so that all the valve sections are co-axially connectedfor rotationin unison. The rotation of these rotors may be effected inany manner well-known in the art. Thus the weight of each valve sectionis supported solely by the bearings at the ends thereof and neither highpressure nor partial vacuum in the engine cylinder effects any change inthe spacing between the periphery of the valve sections and thejuxtaposed casing wall.

In order to maintain the valve sections I2 and the housing II in propergas-tight seating con tact under varying conditions of heat andpressure, the seating section of one of said members is serrated to forma series of V-shaped ridges 25 of small cross-section, extendingtransversely of the direction of relative movement of said members. Inthe construction shown in Figs. 1 and 2,, the main central section ofthe valve section I2 is provided with said ridges 25 along its twoopposed circular peripheral surface portions 26, which are concentricwith the shafts 23, and which are adapted to rotate successively intoseating contact with the lower smooth circular seat 21 of the housing IIextending between th two ports II and I5.

Before the valve has been operated, the ridges 25 may be sharp at theircrown edges or high points 28 asshown in 3, and contact the opposedsmooth surface 21 when cold, and are small enough to be worn down atthese points as shown in Fig. 4 into conforming gas-tight seatingrelationship with said surface 21 after a comparatively short period ofuse, with the valve expanded by heat. As an example, the distancebetween adjacent ridges 25 may be not to exceed of an inch, and theparts so dimensioned and so designed that these ridges will be worn downat their high points to a width of possibly 3 3 of an inch, when theexpansion is at'its maximum and the ridges are in gas-tight engagementwith the seating surface 21 of the housing. Thus it will be seen thatthe areas of the outer faces of the ridges in the serrated areaconstitute only a very small portion of the original area before theserrations are formed, and that the width of the outer face of eachridge, even after wearing away, is only about one third of the distancefrom ridge center to ridge center. As the outer faces of the ridges donot support any load from the weight of the valve or of the pressureapplied to the valve during operation of the engine; it is not importantthat the outer faces of the ridges have any appreciable width. Theridges serve merely as partitions between adjacent grooves. It isimportant that there be a large number of narrow grooves in which minuteed dies of gas may occur and in which there may be a large number ofsuccessive drops in pressure between the cylinder port It and theexhaust port l5. Thus, even though the faces of the ridges may onlylightly contact with, or be even slightly spaced from, the casing wall,there will be practically-no leakage of pressure from the cylinder portto the exhaust port and across the valve seat. It is also important thatthe gas volume of the grooves be very small so that there will be theminimum of high pressure gas carried by each groove in traveling fromthe cylinder port to the exhaust port. This serrate formation betweenthe rotors l2 and the housing reduces to a minimum the contact areabetween these members, thereby materially reducing wear between saidmembers. At the same time, it forms an effective gas-tight seatingcontact between the relatively sliding part without the necessity of theusual expensive and time consuming grinding or machining operations. Theparts grind themselves to the proper fit and with minimum removal ofmetal. v

The valve may expand and contract somewhat; with changes in temperature,for instance, it may be slightly smaller when cold than when heated upafter running for some time When starting the engine, the clearancebetween the valve and its seat around the cylinder ports may be such asto permit slight leakage, but as any such leakage will flow at rightangles to the. serrations, its velocity will be so reduced that theleakage will be negligible. When the valve heats up and expands, thevalve will directly seat around the cylinder port, but the metalsurfaces directly in sliding contact and the friction and wear will begreatly reduced due to the serrations. The sharp edges of the serrationswill act to scrape any accumulation of carbon from the opposite wall andsuch carbon will collect, to some extent, in the grooves. In case anymetal particles be scraped off or dislodged from, or worn off thedirectly contacting metal surfaces, particularly when the parts arefirst assembled and run, such particles will collect in the grooves andwill not act to score the opposing surface. If the bearings II shouldbecome worn, the rotors l2 are apt to be lifted away from their seat andtowards the section of the housing diametrically opposite said seat, bythe pressure of the'gases in the cylinder. Under these conditions, wearof the slide parts is apt to increase, and the rotor is apt to bind orseize in its housing. In order to avoid this condition, the cylindricalvalve chamber 28 of the bore i3 opposite to the port l6 may be ofslightly larger diameter than the valve member l2, and eccentric withrespect to said valve member, which is concentric with the smaller part3| of the bore l3 adjacent to the port 16, and which tangentially seatson the lower surface of said chamber.

There is thus provided a clearance 32 between the valve and the upperpart of said valve chamber. This clearance 32, although shown in Figs.

1 and 2 on an exaggerated scale, actually has a maximum width of only afew thousandths of an inch. The three ports l4, l5 and I6 open into thevalve chamber 28 within the lower semicircular part thereof, and sincethe difference between the diameter of the rotor and that of saidchamber is very small, there will be little or no leakage from one portto another. Such expansion as may occur in the valve will not cause itto grind against the upper surface of the valve chamber orcause it tobind if the upper surface of the valve chamber be slightly eccentric, asabove described. The roller bearings between the successive valvesections prevents the valve as a whole from flexing under high pressurefrom the engine cylinder and there will be substantially no possibleflexing of each valve section between the adjacent roller bearings, dueto the large diameter and short length of said sections.

The outer race rings of the roller hearing are preferably ofthe samediameter or of but slightly larger diameter than the valve section andthus the valve member and its bearings may be assembled as a unit andreadily slid or otherwise moved into position.

If the bearings wear sufficiently to permit slight lifting of the valvesections [2 from their seats, this will not be sumcient to effectcontact between the rotor and the upper part of the enlarged valvechamber 28, so that wear of these relatively slidable parts is reducedto a minimum, and the possibility of jamming or binding of the valverotor is eliminated.

To prevent gas leakage endwise of the valve, each of the rotors or valvesections is provided near each end with. a peripheral groove 35 toreceive a split metal packing ring 36 of the piston ring type,expansible into sealing engagement with the peripheral wall of thehousing I I.

For lubricating the various parts of the valve mechanism, the ends ofthe rotors |2 are spaced from the corresponding ends of the bearings toform lubricant chambers 4| and 42 on opposite sides of each bearing, andthe lower section of the housing H is recessed at spaced intervals toprovide a, sump 43 interconnecting said chambers 4| and 42. Lubricatingoil is introduced desirably under considerable pressure into one of eachadjoining pair 4|, 42 through inlets 44 at the top, and is desirablyexhausted from each sump 43 through a discharge pipe 45 connected to avacuum pump (not shown), which may return the oil to the crank-case ofthe engine. This pump should operate at a higher vacuum than thatproduced in the engine cylinders to prevent the periodic vacuum in saidcylinders from pumping the lubricant to said cylinders. The oildelivered into the chambers 4| and 42 serves to lubricate the bearingsand the shafts 23.

In order to feed lubricating oil to the seating sections of the rotorsl2 and the housing II, and

to the packing rings It, each rotor is provided beyond its serratedportions and on opposite sides of each ring with a pair of circularsections 41 and 48, formed on the periphery with fine shallow screwthreads of comparatively small pitch. The threads of the rotor section41 have a lead or direction; which when the rotors I! are rotated,efl'ects screw feeding of the oil from the chambers ll and 42 along saidthread to the rings 3', to lubricate said ring. The lead of the threadsof the rotor sections ll is such as to pick up what little oil leakspast the rings II, and screw feed it to the valve chambers It tolubricate the slide parts therein. The lead of the threads on the rotorsections 41 and ll to produce the oil feeding eifect above noted dependson the direction of rotation of the rotors. If. for instance. the rotorsI! are driven in counterclockwise direction as viewed in Fig. 2, theright hand pair of rotor sections 41 and it of each rotor will have lefthand threads, while the left hand pair of rotor sections 41 and I! ofsaid rotor V will have right hand threads.

In Fig. 5 is shown a form of rotary valve, in

which the bore lid of housing lid is of uniform diameter throughout itsvalve length, and the rotors l2 flt concentrically in said bore.Although this embodiment of the invention does .not have the eccentricbore enlargements II of Figs. 1 and 2, it has the advantage ofbeingcheaper to manufacture because of the uniformity in the size of thebore Ila. In all other respects, the construction of Fig. 5 may besimilar to that of Figs. 1 and 2.

In the construction of the rotor valve shown in Fig. 6, the seatingsections 26b of the rotors lZb areof smooth cylindrical form, while theself-seating serrations 25b similar to those shown in Fig. 3 are formed'in' the inner periphery of the valve chamber sections of the housingbore lib. These serrations extend along the bottom and top of the valvechamber, and the high sharp points thereof are adapted to be self-wornby the scraping action of the rotors l2b into the shape shown in Fig. 4for gas-tight conforming contact with said rotors. As in theconstruction of Fig. 5. the rotors lib areconcentrically mounted intheir respective valve chambers.

As many changes could be made in the above I construction and manyapparently widely different embodiments of the invention would be madewithout departing from the scope of the claims, it is intended that allmatter contained in the above description or shown in the accompanyingdrawing shall be interpreted as illustrative and not in a limitingsense.

The present invention. insofar as it relates to the lubrication of thevalve, is not herein claimed but is claimed in my copending applicationSerial No. 474,941, flied February 6, 1943.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

l. A rotary valve mechanism for multicylinder, internal combustionengines includin a valve casing member having a plurality of axiallyspaced sets of peripherally spaced ports, one set for each cylinder ofthe engine and each set including an inlet port, an exhaust port and acylinder port, a rotary valve member in said chamber and including aplurality of sections, one section for each set of ports and eachsection having a passage for interconnecting the corresponding cylinderport with the inlet and in said casing for supporting and centering saidvalve member independently of any contact of the valve sections with thecasing, each bearing being disposed between two adjacent valve sectionsfor supporting'the latter, whereby flexing of said valve meinber bypressure exerted thereon through said cylinder ports is prevented andthe sections between said bearings maintained in fixed spacing inrespect to the valve casing except for the changes 'due to expansion andcontraction of the parts. the surface of one of said members havingsmall closely spaced longitudinal serrations for retarding lateral flowof gas from said cylinder port between said members, and the outer partsof said serration being adapted to be worn into conforming substantiallygastight seating contact with the opposed surface of the other member atopposite sides of said cylinder port and to provide faces ofsubstantially less width than that of the grooves between saidserrations.

2. A rotary valve mechanism for multicylinder, internal combustionengines including a valve casing member having a cylindrical chamber ofsubstantially uniform diameter throughout its length and provided with aplurality of axially spaced sets of peripherally spaced ports, one setfor each cylinder of the engine and each set including an lnletport. anexhaust port and a cylinder port, a rotary valve member in said chamberand including a plurality of sections, one section for each-set of portsand each section having a passage for'interconnecting the correspondingcylinder port with the inlet and outlet ports alternately, a pluralityof bearings in said casing for supporting and centering said valvemember, eachbearing being disposed between two adjacent valvesectionsfor supporting both and having an outer race ring, the external diameterof which is but slightly greater than that of the adjacent valvesections whereby the valve sections and roller bearings form a unit ofsubstantially the same diameter throughout its effective length, and

- opposite sides of said cylinder port and of substantially less areathan that ofthe grooves between said serrations.

3. A rotary valve mechanism for multicylinder, internal combustionengines including a valve casing member having a plurality of axiallyspaced sets of peripherally spaced ports,

' one set for each cylinder of the engine and each set including aninlet port, an exhaust port and a cylinder port, a rotary valve memberin said chamber and including a plurality of sections, one section foreach set of ports and each section having a passage for interconnectingthe corresponding cylinder port with the inlet and outlet portsalternately, a plurality of bearings in said casing for supporting andcentering said valve member, each bearing being disposed between twoadjacent valve sections for supporting both, whereby flexing of saidvalve member by pressure exerted thereon through said cylinder port isprevented, said valve casing having portions opposite to said cylinderports disposed eccentrically in respect to the axis of said valve memberto prevent seating of the valve in said outlet ports alternately, aplurality of bearings portions, and each of said valve sections havingthe surface thereon between the ends or said passage provided with'longitudinal closelyspaced grooves whereby the area. of seating surfaceof the valve member and the casing member adjacent to the cylinder portis reduced by over one half and the flow of gas from said port over saidsurface is retarded.

4. A rotary valve mechanism for multi-' cylinder, internal combustionengines including a valve casing member having a plurality of axiallyspaced sets of peripherally spaced ports,

one set for each cylinder of the engine and each set including an inletport, an exhaust port and a cylinder port, a rotary valve member in saidchamber and including a plurality of sections, one section for each setof ports and each section having a passage for interconnectingthecorresponding cylinder port with the inlet and outlet portsalternately, a plurality of hearings in said casing for supporting andcentering said valve member, each bearing being disposed between twoadjacent valve sections for supporting both, whereby flexing of saidvalve member by pres sure exerted thereon through said cylinder port isprevented, said valve casing having portions opposite to said cylinderports disposed eccentrically in respect to the axis of said valve memberto prevent seating of the valve in said portions, and the surface of oneof said members having closely spaced longitudinal serrations withintervening grooves for retarding lateral flow of gas from said cylinderport between said members, and the outer faces of said serration beingin substantially gas-tight seating contact with the opposed surface ofthe other member at opposite sides of said cylinder port, and the widthof each face being only about one half of the width of the adjacentgroove.

5. A rotary valve mechanism for multicylinder, internal combustionengines including a valve casing having a plurality of axially spacedsets of peripherally spaced ports, one set one section for each set ofports and each section having a passage forinterconnecting the corresponding cylinder port and the inlet and outlet ports alternately, aplurality of bearings in said casing for supporting and centering saidvalve member, each bearing being disposed between two adjacent valvesections'for supporting both, whereby flexing of said valve member, byvariations in the pressure exerted thereon through said cylinder port isprevented, said valve casing having portions opposite to said cylinderports spaced from said valve to prevent seating of the valve in saidportions, and each of said valve sections having the surface thereonbetween the ends of said passage provided with narrow closely spacedlongitudinal serrations whereby the area of seating surface of the valvemember and the casing member adjacent to the cylinder port is reduced byover one half and the flow of gas from said port over said surface isretarded when said port is closed by said valve.

7. A rotary valve mechanism for multicylinder, internal combustionengines including a valve casing member having a plurality of axiallyspaced sets of peripherally spaced ports, a rotary valve member in saidchamber and including a plurality of sections, one section for each setof ports and each section having a passage for interconnecting the portsof said set, a plurality of roller bearings in said casing forsupporting and centering said valve member, each bearing being disposedbetween two adjacent valve sections for supporting both, whereby flexingof said valve member, by variation in the for each cylinder of theengine and each set ineluding an inlet port, an exhaust port and acylinder port, a rotary valve in said chamber and including a pluralityof sections, one section for each set of ports and each section having apassage for interconnecting the correspondingcylinder port with theinlet and outlet ports alternately, a plurality of bearings in saidcasing for supporting and centering said valve member, each bearingbeing disposed between two adjacent valve sections for supporting both,whereby flexing of said valve member, by pressure exerted thereonthrough said cylinder port is prevented, and each of said valve sectionshaving the surface thereon between the ends of said passage providedwith narrow, sharp edged longitudinal serrations whereby the area ofseating surface of the valve member on the casing member adjacent to thecylinder port is reduced by substantially less than one half, andwhereby the escape of gas from said port over said surface is retardedwhen said port is closed by said valve.

6. A rotary valve mechanism for multicylinder, internal combustionengines including a valve casing member having a'plurality oi axiallyspaced sets of peripherally spaced ports, one set for each cylinder ofthe engine and each set including an inlet port, an exhaust port and acylinder port, a rotary valve member in said chamber and including aplurality of sections,

pressure exerted thereon through said cylinder port is prevented saidvalve casing having portions opposite to said cylinder ports spaced fromsaid valve to prevent seating of the valve in said portions, and one ofsaid members having narrow closely spaced longitudinal serrations, theouter faces of which are in substantially seating contact with the othermember at opposite sides of said cylinder port of about one half thewidth of the intervening grooves.

8. A rotary valve mechanism for multicylinder, internal combustionengines including a valve casing member having a plurality of axiallyspaced sets of peripherally spaced ports,

a rotary valve member in said chamber and ineluding a plurality ofsections, one section for each set of ports and each section having apassage for interconnecting the ports of said set, a

outer faces of the ridges having substantially gas-tight seating contactwith the other member at opposite sides of said cylinder port, and saidvalve member having substantially annular fine ooves between eachsection and the adjacent bearing to retard flow of gas endwise of saidcasing.

RUDOLPH WEI-IR.

